2,5-二甲氧基-4-氯硝基苯与硫化钠的反应

硫化钠和二硫化钠分别在95%乙醇中与2,5-二甲氧基-4-氯硝基苯反应, 原本期望得到2,5-二甲氧基-4-氯苯胺, 然而对产物结构的1H NMR, 13C NMR, MS以及元素分析结果表明, 2,5-二甲氧基-4-氯硝基苯中的硝基没有被硫化钠和二硫化钠还原成氨基, 而是其中的氯原子被硫离子(或二硫离子)取代, 分别生成了4,4’-硫代-2,2’,5,5’-四甲氧基-双硝基苯和4,4’-双硫代-2,2’,5,5’-四甲氧基-双硝基苯. 根据这个实验事实, 讨论了上述亲核取代反应的机理.     

4-乙酰基-2-硝基苯甲醛的简便合成

从4-乙酰基-2-硝基甲苯出发, 经溴化、羟化、氧化以88.5%的总收率制备得到4-乙酰基-2-硝基苯甲醛.     

The Reaction of 2,5-Dimethoxy-2,5-Dihydrofuran with Dichloroketene

2,5-Dimethoxy-2,5-dihydrofuran (DDF) reacts with dichloroketene to give 7,9-dimethoxy-3,3,5,5-tetrachloro-8-oxabicyclo[4,3,0]-noan-2,4-dione (I), and methyl chloro-(2,5-dihydro-5-methoxy-2-furanylidene) acetate (II). The reactions of 2,5-dihydrofuran and 2,5-dimethoxy-tetrahydrofuran with dichloroketene were also-studied for comparison. Compound II was derived from the insertion of a molecule of dichloroketene into the C-O bond of DDF with subsequent dehydrochlorination. Compound I resulted from the cycloaddition of two molecules of dichloroketene to the C=C bond of DDF. A mechanism involving a 1,5-dipolar intermediate is proposed to account for this novel reaction.     

2,5-Dimethoxy-2,5-dihydrofurans in 1,3-dipolar cycloaddition reactions

Itis shown that 2,5-dimethoxy-2,5-dihydrofurans enter into 1,3-dipolar cycloaddition with benzonitrile N-oxides and with diphenylnitrilimines to form derivatives of 1,3-dimethoxy-6-phenyl-1,3,3a,6a-tetrahydrofuro[3,4-d]isoxazole and 1,3-dimethoxy-4,6-diphenyl-1,3,3a,-6a-tetrahydrofuro[3,4-d]pyrazole, respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 150–151, February, 1971.     

超声法合成3,4-二甲氧基-4'-羟基查尔酮

以3,4-二甲氧基-苯甲醛和对羟基苯乙酮为原料,无水乙醇为溶剂,HCl气体为催化剂,在超声作用下,经Claisen-Schmidt缩合反应合成了3,4-二甲氧基-4′-羟基查尔酮。 产物结构经IR和1H NMR进行了表征,在2种原料摩尔比1∶1投料比条件下,优化的合成条件为超声输出功率240 W,反应温度30 ℃,反应时间20 min,产率达到92.1%,比传统方法反应时间短、操作简便、产率高。     

Synthesis and Structure of Bis(4-nitrobenzaldehyde thiosemicarbazone) Cadmium Iodide

1　INTRODUCTIONTransitionmetalcomplexesofthiosemicarbazoneshavebeenextensivelystud-ied〔1～3〕.Thiosemicarbazoneshavebeenshowntoexhibitvarioustypesofbiologicalactivitywhichinanumberofcasesarethoughttoberelatedtotheirabilitiestochelatemetals.Recently,therehasbeenconsiderableinterestinthechemistryofSchiffbasecompoundscontainingthiosemicarbazonesandtheirIIBgroupmetalcom-plexesduetotheirnonlinearopticalproperties〔4～6〕.Itcouldbeexpectedthatthede-signandsynthesisofIIBmetalcomplexesderived…     

Separation and Determination of 2,5-Dimethoxy-4-Methylamphetamine Enantiomers in Plasma by High-Performance Liquid Chromatography

Abstract

A method for quantitation of 2,5-dimethoxy-4-methylamphetamine (DOM) enantiomers in plasma by high-performance liquid chromatography (HPLC) is described, d- and l-DOM were readily converted to the amides by condensation with a newly developed chiral reagent, succinimidyl ester of l-α-methoxy-α-methyl-1-naphthaleneacetic acid. The yielded diastereomers were separated on the μPorasil column with cyclohexane/ethyl acetate (3:1) exhibiting satisfactory k' and R values. The clean-up procedure by use of Sep-pak C₁₈ and carboxymethyl Sephadex LH-20 (CM-LH-20) proved to be effective for determination of the drug in biological fluids by HPLC. The plasma levels of d- and l-DOM after administration of the racemate to the rabbit were determined by the method thus established.     

2,5-二甲氧基-4-[(1E)-2-(1H-苯并咪唑-2-基)乙烯基]苯甲醛的合成

以2-甲基苯并咪唑(1)和2,5-二甲氧基-1,4-对苯二甲醛(3)为原料,经缩合反应合成了新化合物——2,5-二甲氧基-4-[(1E) -2-( 1H-苯并咪唑-2-基)乙烯基]苯甲醛(4),其结构经1H NMR,IR和ESI-MS表征.较佳缩合反应条件为:1 11 mol,n(1)∶n(3)=1.1∶1.0,回流反应6h,收率75.2％.     

2,5-二溴-4-硝基咪唑的合成

以咪唑为原料,经硝化和溴化反应合成了抗炎药物中间体——2,5-二溴-4-硝基咪唑,总收率80.3%,其结构经1H NMR和IR确认。     

2,5,-Dimethoxy- and 2,5-di-n-butoxy-1,4-benzoquinone reactions and polymerization with 1,6-hexanediamine

The serendipitous formation of 2,5-dimethoxy- 1,4-benzoquinone is reported from the reaction of 1,4-benzoquinone with methanol, DABCO, and paraformaldehyde. This monomer, and its di-n-butoxy analog, are also available from 2,5-dihydroxy-1,4-benzoquinone. These materials are capable of novel polycondensation reactions with diamines such as 1,6-hex-anediamine. Use of m-crexsol as polymerization solvent gave a dark, insoluble product while various amide solvents lead to orange or pink polymers that had average degrees of polymerization from 5 up to >30. These polymers, Plus model compounds obtained from 1-aminopropane and N,N'- dimethyl-1,6-hexanediamine, were characterized by FTIR, solution, and solid-state NMR.     

Synthesis of 3-amino-5-nitrobenzaldehyde phenylhydrazone

Conclusions Conditions were found for the simultaneous reduction of the aliphatic nitro group and the selective reduction of one of the aromatic nitro groups in 3,5-dinitrophenylnitromethane and the previously unknown 3-amino-5-nitrobenzaldehyde was obtained as the phenylhydrazone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2173–2175, September, 1982.     

High-Yield Synthesis of the Novel E,E-2,5-Dimethoxy-1,4-bis[2-(4-ethylcarboxylatestyril)]benzene by the Heck Reaction

The novel E,E-2,5-dimethoxy-1,4-bis[2-(4-ethylcarboxylatestyril)]benzene, 4, was obtained in good yield (92%), by the Heck cross-coupling reaction using Pd(dba)₂ and P(OPh)₃ like catalytic system. The high trans specificity of the product produced by the Heck reaction was confirmed by Fourier Transform–infrared and NMR. The methodology reported can be used as synthetic route for precursors to phenylenevinylene target systems with highly desired functional groups in their molecular structure, such as carboxylic, to build metal–organic frameworks and other applications within the supramolecular chemistry.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

3,4-二甲氧基-6-氨基苯甲醛的合成

以藜芦醛为原料合成4,5-二甲氧基-2-硝基苯甲醛,经铁粉还原后高产率地得到了3,4-二甲氧基-6-氨基苯甲醛。     

2,7-二甲氧基-3,6-二苯氧基萘的合成

以3,6-二溴-2,7-二羟基萘为起始原料,与硫酸二甲酯经甲醚化反应得3,6-二溴-2,7-二甲氧基萘(2);2与苯酚在碘化亚铜催化下经取代反应合成了新化合物——2,7-二甲氧基-3,6-二苯氧基萘,总收率82.5%,其结构经1H NMR,13C NMR,ESI-MS和元素分析表征。     

6,7-二甲氧基-4-哌嗪喹唑啉缩氨基硫脲衍生物的合成及体外抗肿瘤活性研究

以4,5-二甲氧基-2-氨基苯甲酸和醋酸甲眯为起始原料,经环化、氯化、取代和缩合四步反应,设计、合成了六个未见文献报道的含有缩氨基硫脲的喹唑啉衍生物4a～4f,其结构用1H NMR,13C NMR,ESI-MS,IR及元素分析测试技术进行了表征.采用MTT法测试了化合物4a～4f对人胃癌SGC-7901、人口腔表皮样癌KB和人纤维肉瘤HT-1080的体外抗肿瘤活性.初步的测试结果表明,化合物4a和4f对HT1080表现出显著的抗肿瘤活性.     

Synthesis of 2,5-dimethyl- and 1,2,5-trimethyl-4-dimethoxyphosphinylpiperid-4-ols

Dimethyl phosphite is condensed with 2,5-dimethyl- and 1,2,5-trimethylpiperid-4-ones in the presence of alkali metal alkoxides. It is shown that 2,5-dimethyl- and 1,2,5-trimethyl-4-dimethoxyphosphinyl-piperid-4-ols are formed in both cases in the same stereoisomeric forms and in high yields. Methylation of the piperidol isomer which was not substituted at the nitrogen atom indicated that the two piperidols formed had the same configuration.